The low-level laser therapy after maxillary expansion in the c-Fos expression

• Grant number: 13/13051-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2013
• End date: September 30, 2015
• Field of knowledge: Health Sciences - Dentistry - Orthodontics
• Principal Investigator: Maria Bernadete Sasso Stuani
• Grantee: Isabela Mansano Carbinatto
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Objective: the aim of the present in vivo study will be to quantitatively evaluate the effects of low-level laser therapy (LLLT) Gallium-Aluminum-Arsenide (GaAlAs) on pain control after rapid maxillary expansion (RME) in young rats, analyzing the activation of nociceptive related structures, using the c-Fos expression in caudalis, interpolaris, and oralis subnuclei. Materials and methods: a total of 55 rats Wistar (Rattus norvegicus, albinus), male, weighing 220g, were assigned to 4 groups: control group (n=5) with no treatment (no RME and no LLLT); experimental I (n=25) with RME without LLLT. The animals will be euthanized at hours 6, 12, 24, 48, and 72 after RME; experimental II (n=25) with RME and LLLT (54J/cm2). The animals will be euthanized at the same periods described for experimental I. After the experimental periods, they will be anesthetized and perfused with 4% paraformaldehyde. In the sequence, brains will be removed from the skull and processed for FOS immunocytochemistry. Coronal sections through the spinal trigeminal caudalis (SpVc-bregma: -15.96 and -14.28 mm), spinal trigeminal interpolaris (SpVi-bregma: -13.32 mm), and spinal trigeminal oralis (SpVo-bregma: -11.28 mm) will be cut at 40µm thickness on a cryostat. Every third section will be collected in PBS and processed for Fos immunohistochemistry. The Image J software will be also used to quantify Fos-IR neurons in sections of the rat brains. The sections will be analyzed light microscopically (10× objective). The ANOVA and Tukey tests will be used and the significance level was set at 5%.